Initial commit.

nl80211.py

@@ -0,0 +1,168 @@
+#!/usr/bin/python2.7
+
+import collections
+import socket
+import struct
+
+sock = socket.socket(socket.AF_NETLINK, socket.SOCK_DGRAM, 16)
+sock.bind((0,0))
+query = '\34\0\0\0\24\0\5\3\\7\252T\367\16\0\0\21\0\0\0\10\0\3\0\6\0\0\0'
+sock.send(query)
+data = sock.recv(1024)
+
+
+class ParsedData(object):
+  def __init__(self, data):
+    self.data = data
+    self.offset = 0
+
+  def __str__(self):
+    data = self.data[self.offset:]
+    return '(%d bytes): %r' % (len(data), data)
+
+  def Advance(self, offset_incr):
+    self.offset += offset_incr
+
+  def AtEnd(self):
+    return self.offset == len(self.data)
+
+
+class Parser(struct.Struct):
+  def __init__(self, format, fields=None):
+    super(Parser, self).__init__(format)
+    self._fields = fields
+
+  def Parse(self, parsed_data, targetlen=None):
+    if targetlen is not None:
+      assert self.size == targetlen, 'Actual bytes: %d, expected bytes: %d' % (targetlen, self.size)
+    values = self.unpack_from(parsed_data.data, parsed_data.offset)
+    parsed_data.Advance(self.size)
+    if self._fields:
+    	return collections.OrderedDict(zip(self._fields, values))
+    else:
+        assert len(values) == 1
+        return values[0]
+
+
+class StringParser(object):
+  def Parse(self, parsed_data, targetlen):
+    ret = parsed_data.data[parsed_data.offset:parsed_data.offset + targetlen]
+    parsed_data.Advance(targetlen)
+    return ret
+
+
+class EmptyParser(object):
+  def Parse(self, parsed_data, targetlen=None):
+    assert not targetlen
+    return True
+
+
+nlmsghdr = Parser('LHHLL', ('length', 'type', 'flags', 'seq', 'pid'))
+genlmsghdr = Parser('BBH', ('cmd', 'version', 'reserved'))
+
+
+class Attribute(object):
+  _nlattr = Parser('HH', ('len', 'type'))
+
+  def __init__(self, attributes):
+   super(Attribute, self).__init__()
+   self._attributes = attributes
+
+  def Parse(self, parsed_data, targetlen=None):
+    nlattr = self._nlattr.Parse(parsed_data)
+    if targetlen is not None:
+      assert nlattr['len'] == targetlen
+    name, sub_parser = self._attributes.get(nlattr['type'], (None, None))
+    assert sub_parser, 'Unknown attribute type %d, len %d' % (nlattr['type'], nlattr['len'])
+    sub_len = nlattr['len'] - self._nlattr.size
+    ret = {
+      name: sub_parser.Parse(parsed_data, sub_len)
+    }
+
+    padding = ((nlattr['len'] + 4 - 1) & ~3) - nlattr['len']
+    parsed_data.Advance(padding)
+
+    return ret
+
+
+class Attributes(object):
+
+  def __init__(self, attributes):
+    super(Attributes, self).__init__()
+    self._attribute = Attribute(attributes)
+
+  def Parse(self, parsed_data, targetlen=None):
+    if targetlen is None:
+      local_parsed_data = parsed_data
+    else:
+      local_parsed_data = ParsedData(parsed_data.data[parsed_data.offset:parsed_data.offset + targetlen])
+      parsed_data.Advance(targetlen)
+    ret = collections.OrderedDict()
+    while not local_parsed_data.AtEnd():
+      ret.update(self._attribute.Parse(local_parsed_data))
+    return ret
+
+
+flag = EmptyParser()
+string = StringParser()
+u8 = Parser('B')
+u16 = Parser('H')
+u32 = Parser('L')
+u64 = Parser('Q')
+
+
+sta_flag_authorized = 1 << 0
+sta_flag_short_preamble = 1 << 1
+sta_flag_wme = 1 << 2
+sta_flag_mfp = 1 << 3
+sta_flag_authenticated = 1 << 4
+sta_flag_tdls_peer = 1 << 5
+sta_flag_associated = 1 << 6
+
+rate_info = Attributes({
+  1: ('bitrate', u16),
+  2: ('mcs', u8),
+  4: ('short_gi', flag),
+  5: ('bitrate32', u32),
+  9: ('80p80_mhz_width', u32),
+  10: ('160_mhz_width', u32),
+})
+
+bss_param = Attributes({
+  2: ('short_preamble', flag),
+  3: ('short_slot_time', flag),
+  4: ('dtim_period', u8),
+  5: ('beacon_interval', u16),
+})
+
+sta_info = Attributes({
+  1: ('inactive_time', u32),
+  2: ('rx_bytes', u32),
+  3: ('tx_bytes', u32),
+  7: ('signal', u8),
+  8: ('tx_bitrate', rate_info),
+  9: ('rx_packets', u32),
+  10: ('tx_packets', u32),
+  11: ('tx_retries', u32),
+  12: ('tx_failed', u32),
+  13: ('signal_avg', u8),
+  14: ('rx_bitrate', rate_info),
+  15: ('bss_param', bss_param),
+  16: ('connected_time', u32),
+  17: ('sta_flags', Parser('LL', ('mask', 'values'))),
+  18: ('beacon_loss', u32),
+  23: ('rx_bytes_64', u64),
+  24: ('tx_bytes_64', u64),
+})
+
+nl80211_attr = Attributes({
+  3: ('ifindex', u32),
+  6: ('mac', string),
+  21: ('sta_info', sta_info),
+  46: ('generation', u32),
+})
+
+parsed_data = ParsedData(data)
+print 'nlmsghdr: %s' % nlmsghdr.Parse(parsed_data)
+print 'genlmsghdr: %s' % genlmsghdr.Parse(parsed_data)
+print 'nl80211_attr: %s' % nl80211_attr.Parse(parsed_data)